<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>数学运算</title>
	<script type="text/javascript">
		var a = 30;
		var b = 7;

		// 求模，也就是求余
		var c = a%b;

		var d = 0;

		var e = d%b;

		alert(c); //弹出2
		alert(e); //弹出0
	</script>
</head>
<body>
	
</body>
</html>